<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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Answer:
Photosystem I (PS-I )and photosystem II (PS-II ) are two multi-protein complexes. These complexes contain the pigments used to absorb, harvest and catalyze the photons and light energy in the photosynthetic reactions. The main purpose of photosynthesis reactions to produce high chemical energy compounds.
Photosystem I and II are different from each other because of their absorbing wavelength of light. PS-I absorbs the longer wavelength of light than PS-II.
PS-I plays the major role in the production of high energy carriers ATP and NADPH using light energy (700 nm).
PS-II plays its function in the hydrolysis of water and ATP synthesis using light energy (680 nm).
Answer:
D. The man is one hundred thousand times larger than the amoeba.
Explanation:
one meter is equal to 1,000,000 micrometers.
(1.7m * 1,000,000)/17 = 100,000
Answer:
D) An original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
Explanation:
- Semi-conservative replication refers to two strands of DNA unzip, and a new strand is assembled onto each 'conserved' strand.
- The replicated double helix consists of one old strand and one newly synthesised strand.
- It describes the structure of DNA, a twisted helix of two strands with bases joining the strands.
